In industries involved in the sale of liquid products, especially liquid products of low cost, it is highly desirable to achieve rapid and successive filling of containers such as bottles, cans, drums and the like with liquid material while at the same time maintaining the cost of the filling operation per container as low as possible. Although rapid container filling systems have been in use for a considerable period of time, one of the principle problems that is typically encountered is the inability to achieve rapid filling and at the same time prevent any spillage of the liquid being filled. As container filling operations are in progress, the filler heads that are employed typically accumulate a quantity of the liquid being dispensed. Obviously in some cases the liquid is quite thin and in other cases the liquid may have considerable viscosity. At the end of a container filling cycle, when the container and filling head are separated, the accumulated liquid will descend along the outside surfaces of the filling head and drip from the filling head. It is not unusual where highly productive container filling equipment is in use, to find substantial accumulation of the liquid product on the floor and equipment in the immediate vicinity of the filling operation. It is well known that in order to minimize drips of fluid from filling heads packaging companies or users of filling equipment will slow down the cycle time of the equipment in order to help compensate for drips. Slowing of the cycle time in this manner does not eliminate drips but permits a greater percentage of the drips to fall inside the containers. Obviously, slowing down the cycle time in this manner adversely affects the productivity of the container filling equipment and thereby adversely affects the potential profit of the packaging process. It is desirable, therefore, to provide container filling equipment that eliminates all drips and thereby permits the users of the equipment to achieve maximum cycling speed of the equipment to therefore increase production rates substantially.
Obviously, the loss of any of the liquid being filled becomes a commercial disadvantage not only from the standpoint of loss of the liquid material but also from the standpoint of maintenance costs for cleaning the drip or spilled liquid from the floor and equipment. Even further, the presence of liquid on the floor and equipment can subject workers to considerable hazards form the standpoint of injuries due to slipping and falling and from the standpoint of environmental contamination. Under circumstances where drippage or spillage of liquid can be prevented during rapid container filling operations, the commercial aspects of the filling operation will be materially enhanced by minimal loss of product, by savings and cleaning costs and the costs of insurance such as liability, workmen's compensation insurance, etc. Also, during container filling operations, any drippage from the filling heads will likely fall onto the exterior surfaces of certain ones of the containers being filled. If any of the containers become contaminated with the liquid material being filled, it is typically necessary to clean all of the containers, thereby adding considerable filled container cleaning expense to the filling operation. It is desirable, therefore, to provide container filling heads for filling machines which are specifically designed to eliminate any possibility of drippage to thereby promote rapid filling of containers while minimizing the overhead costs that are typically inherent in conventional container filling operations.
During container filling the external surfaces of the filling head will typically collect liquid such as by liquid splashing, liquid foaming, etc. When each filling operation has been completed, the filling head withdrawn from the container and the filled container replaced with an empty one, the collected liquid on the exterior of the filling head will run down the exterior surface. In the case of filling heads such as set forth in U.S. Pat. No. 4,749,010, even though a vacuum drip recovery system is employed which incorporates a tapered dispensing tip having an internal suction passage, some of the downwardly draining liquid material from the entire external surface of the filling head will bypass the vacuum drip recovery system and fall from the filling head. It is desirable therefore to provide a system for removing any external accumulation of liquid from a major portion of the filling head as it is being withdrawn from the container so that upon clearing the container the filling head, except for its lower tip will be free of any descending liquid, only the accumulation of liquid present on the dispensing tip will be subject to vacuum recovery, which is easily accommodated.